Fuse block



H. J. L. FRANK Nov. 24, 1931.

FUSE BLOCK Filed Aug. l2 1925 Patented Nov. 24, 1931 UNITED STATES PATENT OFFICE HARRISON J'. L. FRANK, DETROIT, MICHIGAN, ASSIGNOR TO BULLDOG ELECTRIC PROD- UCTS COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF WEST VIRGINIA FUSE BLOCK Application med August 12, 1925. serial No. 49,709.

This invention relates to fuse blocks.

An object of the invention is a fuse block having a depression, a socket shell therein, a center contact within the shell and connected to a bus bar, and a slot of substantial size in a wall of the depression, opening only on a side of the shell to permit testing of a fuse plug within the shell to see Whether or not it has been blown.

Still further objects will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings, in which Fig. 1 is a fragmentary plan view of the fuse block.

Fig. 2 is a section on the line 2 2 of Fig. 1.

As indicated on the drawings, the fuse block 10 which is of insulating material has a depression 11 in which is disposed a socket shell 12. Under the block is a bus bar 14 into which is threaded a screw 16 Whose head 18 forms a center contact for the plug fuse, not shown, the screw being insulated from the bottom of the shell by an insulating washer 20. Passing thru aligned apertures 22 and\23 in the block and in the side Wall of the shell 12 is a conductor 24 whose bared end 25 is electricall connected to the bottom of the shell by a inding screw 26.

The construction thus far described is more or less conventional and forms no part of the present invention by itself.

As indicated best in Fig. 2, the block is provided with a slot 30 of substantial size leading from the top face of the block and opening only on the side of the shell. This slot permits the entrance of one of a pair of test leads, indicated diagrammatically at 33, into engagement with the side wall of the shell even while a use plug is in place in the socket. Another test lead, indicated diagrammatically at 3 4, is adapted to be brought into contact with the bus bar 14, and it will be seen that these test leads bridge the fuse plug while it is in place and permit testing thereof.

i N ow having described the invention and the preferred embodiment thereof, it is to he understood that the said invention is to he limited, not to the speciic details herein set shell, and-opening only to the inside of said depression, the slot serving as an entrance for one of a pair of test leads, the center contact being of different polarity with respect to the shell and being adapted to be electrically con nected to the other one of the pair of test leads, the shell itself preventing a test lead which is entered into said slot from bridging the gap between the shell `and the center contact and causing a. short circuit between them.

2. In a fuse block, a depression, a socket shell therein, a center contact Within said shell and connected to a bus bar, and a slot of substantial size in a wall of said depression, opening only on the side of the shell to permit testing of a fuse plug within said shell to see whether or not it has been blown, the

slot and the bus bar enabling the fuse plug to be tested while it is within the shell.

HARRISON J. L. FRANK. 

